mail.madhoster.com has no CNAME records.
Question and response
Question
dig mail.madhoster.com. NS
Answer
The response has no answer records.
Authority
madhoster.com. 3562 SOA nserver1.madhoster.com. hostmaster.madhoster.com. 2014040277 10800 3600 1209600 10800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0